Around 550 former corporate employees of Z Energy may be owed money after historical holiday pay recalculations.
The company has investigated its payroll system, and discovered it may not have implemented the Holidays Act correctly.
It is seeking around 550 former permanent, fixed term and casual employees who worked for Z Energy, Z Energy 2015 Limited or Chevron NZ since January 1 2014 to find out if they are owed money.
It is expecting to pay out around $1.3 million in total.
"We have always taken pride in the way we look after our people, and in this instance, we have let them down," said general manger for people and culture Helen Sedcole.
"For that, we are incredibly sorry. Our focus right now is to put things right for both previous and current employees while ensuring our payroll system and processes are updated so that this does not occur in the future."
The miscalculation has affected a number of employers, including Auckland Transport and Stuff.